You seem to be talking exclusively about the comfort of well-educated people who would prefer to live in the US and have the resources to emigrate, rather than the survival of humankind.

Let me make it utterly clear: I am absolutely talking only about the survival of the American economy.

I'm a descendent of immigrants born to poor circumstances. I'm lucky to be here as a result of getting past strict immigration policies. But I gotta be real, If America tried to "save" every one on the face of the earth by letting everyone in need into this country, we'd probably triple our population, and change the state of everything.